We investigate the temperature induced ferromagnetic to paramagnetic phase transition in Co substituted La(FexCoySi1- x-y)13 with x = 0.9 and low Co content of y = 0.015 (Tc?200 K) by means of magneto-optical imaging with indicator film and by calorimetry at very low temperature rates. We were able to visualize the motion of the ferromagnetic (FM)/paramagnetic (PM) front which is forming reproducible patterns independently of the temperature rate. The average velocity of the FM/PM front was calculated to be 10-4 m/s during the continuous propagation and 4×10-3 m/s during an avalanche. The heat flux was measured at low temperature rates by a differential scanning calorimeter and shows a reproducible sequence of individual and separated avalanches which occurs independently of the rate. We interpret the observed effects as the result of the athermal character of the phase transition.

Dynamics of the magneto structural phase transition in La(Fe0.9Co0.015Si0.085)13 observed by magneto-optical imaging / Kuepferling, Michaela; Bennati, C.; Laviano, F.; Ghigo, G.; Basso, Vittorio. - In: JOURNAL OF APPLIED PHYSICS. - ISSN 0021-8979. - 115:17(2014), p. 17A925. [10.1063/1.4866880]

Dynamics of the magneto structural phase transition in La(Fe0.9Co0.015Si0.085)13 observed by magneto-optical imaging

KUEPFERLING, MICHAELA;BASSO, VITTORIO
2014

Abstract

We investigate the temperature induced ferromagnetic to paramagnetic phase transition in Co substituted La(FexCoySi1- x-y)13 with x = 0.9 and low Co content of y = 0.015 (Tc?200 K) by means of magneto-optical imaging with indicator film and by calorimetry at very low temperature rates. We were able to visualize the motion of the ferromagnetic (FM)/paramagnetic (PM) front which is forming reproducible patterns independently of the temperature rate. The average velocity of the FM/PM front was calculated to be 10-4 m/s during the continuous propagation and 4×10-3 m/s during an avalanche. The heat flux was measured at low temperature rates by a differential scanning calorimeter and shows a reproducible sequence of individual and separated avalanches which occurs independently of the rate. We interpret the observed effects as the result of the athermal character of the phase transition.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11696/51068
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